Information Processing Letters
Information Processing Letters > 1999 > 70 > 2 > 53-55
Information Processing Letters > 2005 > 94 > 1 > 37-41
Information Processing Letters > 2007 > 102 > 2-3 > 108-112
Information Processing Letters > 2014 > 114 > 12 > 676-679
Information Processing Letters > 2016 > 116 > 11 > 668-673